Treatment of wet spun protein products



Jan. 8, 1946.

G. 5. DE KADT TREATMENT OF WET SPUN PROTEIN PRODUCTS ,Filed Feb. 19, 1941 i 6. $.05 KADT Mon/my.

Patented Jan. 8, 1946 TREATMENT OF WET SPUN PROTEIN PRODUCTS George Stephan de Kadt, Leeuwarden, Netherlands; vested in the Alien Property Custodian Application February 19, 1941, Serial No. 379,672

In the Netherlands December 27, 1939 7 Claims.

This invention relates to a process for treating with water vapor or steam products such as fibers,

filaments, threads, bands, films and the like and the like obtained by extrusion into a coagulating bath, of a protein solution, which has been prepared with the aid of alkali. According to that process'the products-are subjected to the action of steam or water vapor, if desired, in admixture with other vapors or gases, before the products are introduced into a hardening bath. By that process a considerable improvement of the mechanical properties of these products is obtained. It seems that this result is due to the fact that by the treatment with water vapor, water condenses on the products, but I do not wish to be limited to any definite theory for the explanation of the phenomenon.

It is the object of my present invention to provide an improved and effective method for carrying out this treatment with water vapor of the products obtained by extrusion into a coagulatin bath of protein solutions, particularly solutions of casein and other globular proteins, which have been prepared with the aid of alkali.

Another object of my invention is the provision of a method of treating the extruded products under such conditions that the certainty of successful operation and improved results are assured.

Another object of 'my invention is to provide out in a particularly advantageous manner by causing the water vapor to act on the products while they are moving over at least one vertically arranged pair of horizontal rollers. If desired, the steam or water vapor may be mixed with other vaporous or gaseous substances influencing the properties of the products, for example those having a hardening action, such as for instance ammonia, methanol, sulfur dioxide,

alcohol, carbon dioxide, etc.

In carrying out my invention, I prefer to immerse the bottom roller in a bath, for it has been found that there drops down from the rollers a spinning bath residue diluted by condensed water vapor and having an acid concentration of approximately two thirds of that of the spinning bath. For example, in using a-spinning bath containing 6% of acetic acid and 20% of sodium sulfate the first bath residue dropping down from the rollers contains approximately 4% of acetic acid and 16% of sodium sulfate. The layer of spinning bath diluted bythe condensation of the water vapor surrounds the thread bundles and exerts a uniform and compensating influence, which is not the case with a horizontal arrangement of the pairs of rollers, which causes formation of drops and accumulation of liquid at the bottom side of the thread bundles.

As I hav described in my copending application Serial No. 257,029 the steam or water vapor may be made to act on the products by directing a steam jet onto the prcducts, but the rollers over'which the products are passed according to my present invention may also be arranged in a room in which a damp and more or less warm atmosphere prevails, which is preferably obtained by blowing steam into the room. It is not necessary to obtain a high temperature by means of the water vapor since the favorable action is effected even at a temperature as low as approximately 40 C. I

I have further found that a uniform impregnation of the thread with the diluted spinning bath can be obtained in a still better manner by immersing the bottom roller in the diluted spinhing. bath. It will be obvious that in carrying out the treatment with water vapor on a, number of pairs of rollers the acid and salt concentration decreases gradually.

In treating the freshly spun threads care has to -be taken that by the action of the water vapor and the condensation caused thereby the decrease of the salt concentration is not too great, be-

cause in that case the threads will swell again; On the other hand it is of importance to remove as much as possible residual spinning bath, particularly the acid, in order not to contaminate 4 the hardening baths. For this purpose a salt solution, such as one containing sodium sulfate in an amount of approximately 10-15% can be used as a bath in which the rollers revolve.

I have found that the presence of some methanal is not objectionable, so that according to my invention from an economical viewpoint use of the spent hardening bathwhich apart from -rollers comprising a from the threads. In some cases it is desirable to dissolve first a small amount of salt in this washing water, since it is desirable that its salt content corresponds'to that of the hardening baths, which in the case of sodium sulfate contain aboutof salt. Obviously, however, also other salts and other quantities may be used.

In the drawing:

Fig. 1 is a diagrammatic side view of an em-. bodiment for carrying out the process according to the invention;

some tension is maintained, the thread is stretched because by its plasticity and a kind of threads are spun. By using a number of pairs of rollers this stretching can be carried out best by v giving every subsequent pair of rollers a higher Fig. 2 is a diagrammatic side view of a pair of rollers with another arrangement of the steaming device;

Fig. 3 is a diagrammatic side view of a pair of bottom roller revolving in a bath; i

Fig. 4 is a diagrammatic front view of a pair of rollers around which the threads are conducted several times;

Fig. 5 is a diagrammatic side view of a curling device comprising a profiled top roller of the pair of rollers, which cooperates with a profiled third roller;

Fig. 6 is a diagrammatic side view of a curling device comprising a profiled top roller of the pair of rollers, which cooperates with a third rubber roller;

Fig. 7 is a diagrammatic front view of a pair of conical rollers for stretching the thread; and

Fig. 8 is a diagrammatic front view of a pair of stepped rollers for stretching the thread.

According to Fig. 1 the protein solutionis ex truded into spinning paths 1 through series of spinnerettes 2, the single thread bundles being drawn away by drawing rollers 4. Thegcombin'ed thread bundles 5 are passed over vertically arranged pairs of horizontal rollers 6 and the liquid dripping from the threads and the rollers is collected in baths 1.. From the perforated tube 8 arranged between the two pairs of rollers steam is blown onto the moving threads which are conducted over a dosing roller 9 to a cutting device not shown.

Fig. 2 illustrates how the steam pipe 8 may be arranged between the rollers of one pair and Fig.

3 shows the embodiment in'which the bottom roller 6 revolvesin the bath I.

In order to avoid alarge number of pairs of rollers the threads may be wound around the rollers several times, which embodiment is illustrated by Fig. 4 in which the numerals indicate the same parts as in the Figures 1-3. In this case 'the threads may beseparated with the aid of thread guides or other means.

According 'to my invention the products can be roller of the pair a profile roller cooperating with 2. third roller. Fig. 5 shows how the top roller 6 speed than the preceding pair. In using a limited number'of pairs of rollers the same result can be obtained by application of conical or staged rollers. Fig. shows how the thread is passed several times around a pair of conical departing from the invention or rollers l0 and Fig. 8 illustrates how the same result may be obtained by using stepped rollers I 1.

Various changes may be made in the details disclosed in the foregoing specification without sacrificing the advantages thereof.

I claim:

1. The, process which comprises extruding an alkaline protein solution into a coagulating bath; thereupon conducting the extrudedv product through a path comprising substantially vertical portions; and subjecting the said product, as it is conducted through the said path, to the action of anfr mds'phere which is at least 40 Gianni substantially saturated withwater vapor.

2'. The. process'which comprises extruding an alkaline protein solution into 'a coagulatingv bath, thereupon conducting the extruded product through a path comprising substantially vertical portions; and blowing steam onto said product as it is conducted through the saidpath.

3. The process which comprises extruding an alkaline protein solution into a coagulating bath; thereupon conducting the extruded product through a path comprising substantially vertical portions; subjecting the said product, as it is conducted downwardly through the said path, to the action of an atmosphere which is at least 40 C. and substantially saturated with water vapor; and immersing the said product in a salt solution at the lowest part of said path.

4. The process which comprises extrudingan alkaline protein solution into a coagulating bath; thereupon conducting the extruded product through a path comprising substantially vertical portions; subjecting the said product, as it is conducted downwardly through the said path, to the action of an atmosphere which is at least 40 C. and substantially saturated with water vapor; collecting, at the lowest part of said path, drippings from said product along said substantially vertical portions; and immersing the said product in said collected drippings at the lowest part of of a pair of. rollers is a profiled roller cooperating with an additional profiled roller [2. A thread 5 passes between the rollers B and I2 is treatedwith steam from the pipe 8. Fig. 6 shows a similar.

curling device consisting of the profiled top roller 6 of the pair of rollers, which cooperates with a said path.

5. The process as defined in claim 1 in which 'methanal is mixed with the water vapor while the product is conducted through a path comprising substantially vertical portions.

6. The process as defined in claim 1 in which sulfur dioxide is mixed with the water vapor while the product is conducted through a path comprising substantiallyyertical portions.

7. The process as defined in claim 1 in which alcohol is mixed with the water vapor while the product is conducted through a path comprising substantially vertical portions.

GEORGE STEPHAN DE KADT. 

